Hydroquinone derivatives which release development inhibitors (so-called DIR-hydroquinones) in accordance with the density of the image during development, or hydroquinone derivatives which release silver halide solvents in accordance with the density of the image during development, or sulfonamidophenol derivatives or hydroquinone derivatives which release diffusible dyes in accordance with the amount of silver developed during development are generally known compounds which release photographically useful groups in accordance with the density of the image during development.
The compounds disclosed, for example, in U.S. Pat. Nos. 3,379,529, 3,620,746, 4,377,634 and 4,332,878, JP-A-49-129536, JP-A-56-153336 and JP-A-56-153342 such known of DIR-hydroquinones. (The term "JP-A" as used herein signifies an "unexamined published Japanese patent application".) The compounds disclosed in U.S. Pat. No. 4,459,351 known hydroquinone derivatives which release silver halide solvents. Furthermore, the compounds disclosed in U.S. Pat. Nos. 3,698,897 and 3,725,062 known hydroquinone derivatives which release diffusible dyes. The compounds disclosed, for example, in Yuki Gosei Kagaku Kyokaishi 39, 331 (1981), Kagaku no Ryoiki, 39, 617 (1981), Kino Zairyo, 3, 66 (1983), Photographic Science and Engineering, 20, 155 (1976), Angew. Chem. Int. Ed. Eng., 22, 191 (1983), Yuki Gosei Kagaku Kyokaishi 40, 176 (1982) and Monthly Reports of the Japanese Chemical Society 35, (11), 29 (1982) give known examples of sulfonamidophenol derivatives.
The applications of the compounds indicated above are diverse, depending on the photographic effect of the photographically useful group which is released. However, the functions which are required at the redox nuclei at which the redox reactions occur upon which release of the photographically useful groups take place have many common areas. Thus, the importance of obtaining high quality photographs quickly, easily and in a stable manner has increased and the aforementioned compounds have had to meet these objectives or they have been used for their supplementary action. The common performance required at the redox nuclei of the above mentioned compounds is such that the photographically useful groups can be released efficiently in a short period of time.
The performance which is required at these redox nuclei is described in detail below. First, the rate of the cross-oxidation reaction with the oxidized form of the developing agent or auxiliary developing agent which is formed during development, or the rate at which it reduces the silver halide or other silver salt directly to form the oxidized form, must be sufficiently high so that these redox nuclei exhibit adequate activity during development processing. Secondly, the rate at which the photographically useful groups are released from the oxidized forms of the redox nuclei which have been formed in this way should be high, and release must take place efficiently.
Now, the first criteria mentioned above is satisfied satisfactorily by the known compounds disclosed in the references mentioned above, but the second point, namely the rate at which the photographically useful groups are released from the redox nucleus, and the efficiency, is unsatisfactory with the known compounds disclosed in the references mentioned above, and it is thought that the color forming function could be greatly accelerated if the release rate and the efficiency could be improved.